Tool for rethreading bolts



H. G. SHAEFER ET AL TOOL FOR RETHREADING BOLTS Filed Jan. 21, 1921 I74 (/6 72 507 15.- Hermam G Sciawfer,

Fr077% L- 5777215.

Patented Nov. 9, 1926.

UNETEN STATES rarest sates.

HERMAN SCHAEFER, OF MINNEAPOLIS, MINNESOTA, AND FRANK L. .SMITI-I, F AVON, SOUTH DAKOTA.

TOOL FOR RETI-IREADING BOLTS Application filed January 21, 1921. Serial No. 429.044..

Our invention relates to tools forv rethreading bolts and has for its ob ect to provide a tool for rethreading bolts with stripped, deformed or rusty threads whereby the bolts may be rendered usable.

provide a tool for the purpose where, by reason of an awkward position of the bolt, it would be impossible to accomplish the re-' threading operation by the ordinary means employed.

It is a further object of our invention to provide a tool adapted to engage a bolt having a round head by firmly grasping the head of the bolt to prevent the same from turning when the bolt is of a construction and is in a position that it cannot be engaged and held by a wrench or ordinary means.

In carrying out our invention we providea device which may be grasped in one hand and formed with a pair of arcuate .jaws pivotally connected together and adapted to enage the thread on the opposite sides of the colt and opposite faces of the thread, the rethreading operation being performed by ro tating the device on the bolt.

he full objects and advantages of our invention will'appear in connection with the detailed description thereof and are partlcularly pointed out in the claims.

In the drawings, illustrating the application of our invention in one form Fig. 1 is a plan view of our improved rethreading tool arranged in position on a bolt.

Fig. 2 is a side elevation of the same arranged in position on a bolt.

Fig. 3 is a front elevational View, showing the jaws of the device positioned upon the thread of a bolt.

Fig. 4 is similar view with parts broken away.

Fig. .3 is a plan view of a round headed bolt held by our device, some parts of the device being broken away.

Referring to the drawings, A and B designate the members comprising our device which extend in cross relation to each other, and are pivotally connected to each other near the front. The front ends of the members A and B are provided with jaws and 11 respectively arranged in overlapping relation to one another so that they may be moved to vary the distance between the arcuate cutters. The confronting faces of said jaws are provided with arcuate recesses 12 and 13 respectively, ofthe same diameter,

the diameter thereof being determined by the size of the bolt upon which the device is de- It is a primary object of our invention to' signed to be operated. The arcuate portions can be made any suitable size to various sized bolts.

The rear ends of the members A and B form handle members 14: and 15. The same are curved slightly towards each other from their pivotal connection so that when the two jaws of the device are brought together into engagement with a bolt C, the handle members are in close relation to each other and may be grasped by one hand and rotated about the bolt.

The edges of the recesses 12 and 13 are beveled on both sides to provide a sharp cutting edge on each of the jaws. The inner sides are beveled close to the outer side so as to bring the cutting edge near the outer side of a jaw member. In this manner the confronting edges of the jaws are spaced apart sufiiciently to engagethe thread of the bolt on the opposite sides in performing the function of rethreading or reshaping the thread of the bolt. The edges of the arcuate recesses 12 and 13 are provided with inwardly projecting cutting and shaping teeth 16. The teeth 16 are formed with a broad face and cutting edge 17. The broad face of the teeth forms guides which serve to hold the jaws as they are rotated upon the bolt while they scrape or cut and reform the threads to their normal shape.

The outer ends of the jaw members are curved inwardly terminating with the inner edge of the arcuate recesses, thus providing sharp pointed ends, the purpose of which is to adapt the tool to be used for grasping a round bolt head to prevent the same from turning, as shown in Figure 5, where the position of the bolt prevents the same from being held against rotation by ordinary means.

The operation and advantages of our invention will be obvious in the foregoing description. Our rethreading tool is adapted to be used in a peculiar manner making its use distinctly different than a. rethreading die for cutting threads where it would be impractical to rethread bolts in the ordinary manner. The jaws of our device are of hardened steel and the peculiar shape in to adapt it construction is. designed to provide a tool of' simple, inexpensive construction which can be quickly used to reshape the threads of a bolt with a small amount of labor and in such a convenient manner as to make the tool very desirable for this particular use. The inexpensive, simple construction provides a tool which can be supplied at a small cost to the workmen engaged in the use of bolts for various purposes, thereby effecting the saving in many instances of bolts which are only slightly damaged.

This has proved our tool to be of a very practical nature, being distinctly different in its simple function. It is of primary importance that our device can be used for reshaping and re-forming the thread of a bolt, in many instances, Without removing the bolt from its position.

WVe claim:

1. A rethreading tool comprising a pair of jaws formed of relatively thin flat material, a single serrated beveled edge formed on each of said jaws for engaging the bolt thread and means for forcing said jaws together.

2. A rethreading tool comprising a pair of members pivot-ed in cross relation to each other, a pair of flat thin jaws formedon one end of said members, inner arcuate thread engaging edges formed on said jaws, and a series of long-edged teeth formed'on said edges.

3. A rethreading tool comprising a pair of relatively thin fiat jaws pivoted together,

HERMAN Gr. SGHAEFER. FRANK L. SMITH. 

